
%twofieldshash = (
"ca" => "Tape cartridge",
"cb" => "Chip cartridge",
"cc" => "Computer optical disc cartridge",
"cf" => "Tape cassette",
"ch" => "Tape reel",
"cj" => "Magnetic disk",
"cm" => "Magneto-optical disc",
"co" => "Optical disc",
"cr" => "Remote",
"cu" => "Unspecified",
"cz" => "Other electronic resource",
"da" => "Celestial globe",
"db" => "Planetary or lunar globe",
"dc" => "Terrestrial globe",
"de" => "Earth moon globe",
"du" => "Unspecified globe",
"dz" => "Other globe",
"ad" => "Atlas",
"ag" => "Diagram",
"aj" => "Map",
"ak" => "Profile",
"aq" => "Model",
"ar" => "Remote-sensing image",
"as" => "Section",
"au" => "Unspecified map",
"ay" => "View",
"az" => "Other map",
"ha" => "Aperture card",
"hb" => "Microfilm cartridge",
"hc" => "Microfilm cassette",
"hd" => "Microfilm reel",
"he" => "Microfiche",
"hf" => "Microfiche cassette",
"hg" => "Microopaque",
"hu" => "Unspecified microform",
"hz" => "Other microform",
"mc" => "Film cartridge",
"mf" => "Film cassette",
"mr" => "Film reel",
"mu" => "Unspecified motion picture",
"mz" => "Other motion picture",
"kc" => "Collage",
"kd" => "Drawing",
"ke" => "Painting",
"kf" => "Photo-mechanical print",
"kg" => "Photonegative",
"kh" => "Photoprint",
"ki" => "Picture",
"kj" => "Print",
"kl" => "Technical drawing",
"kn" => "Chart",
"ko" => "Flash/activity card",
"ku" => "Unspecified graphic",
"kz" => "Other non-projected graphic",
"gc" => "Filmstrip cartridge",
"gd" => "Filmslip",
"gf" => "Other filmstrip type",
"go" => "Filmstrip roll",
"gs" => "Slide",
"gt" => "Transparency",
"gz" => "Other projected graphic",
"ra" => "Surface", 
"rb" => "Airborne",
"rc" => "Spaceborne",
"rn" => "Not applicable",
"ru" => "Unknown projected graphic",
"rz" => "Other projected graphic",
"fa" => "Moon",
"fb" => "Braille",
"fc" => "Combination",
"fd" => "Tactile, with no writing system",
"fu" => "Unspecified",
"fz" => "Other tactile material",
"va" => "Beta",
"vb" => "VHS",
"vc" => "U-matic",
"vd" => "EIAJ",
"ve" => "Type C",
"vf" => "Quadruplex",
"vg" => "Laserdisc",
"vh" => "CED",
"vi" => "Betacam",
"vj" => "Betacam SP",
"vk" => "Super-VHS",
"vm" => "M-II",
"vn" => "Not applicable",
"vo" => "D-2",
"vp" => "8mm",
"vq" => "Hi-8 mm",
"vu" => "Unknown video-recording",
"vv" => "DVD",
"vz" => "Other video-recording",
"sda" => "3 in. disc",
"sdb" => "5 in. disc",
"sdc" => "7 in. disc",
"sdd" => "10 in. disc",
"sde" => "12 in. disc",
"sdf" => "16 in. disc",
"sdg" => "CD",
"se" => "Cylinder",
"sg" => "Sound cartridge",
"si" => "Sound-track film",
"sq" => "Roll",
"ss" => "Sound cassette",
"st" => "Sound-tape reel",
"su" => "Unspecified",
"sw" => "Wire recording",
"sz" => "Other sound recording"
);

